Superior and inferior venacave collects blood from various parts of body like lung , kidney , et .and take them to heart .the. Blood the. Reaches to right auricle then biscuspid valve forces it to right ventricle and tricuspid valve to left aurilce and left ventrilce then system and body blood circulation takes place .pulmonary vein takes inoxidized blood to lungs for purification and sends oxydized blood from pulmonary artery .then aaorts sends all the pirified blood to whole body. This is how all blood circulation takes place
Oxygen poor blood enters the right atrium through the vena cava and travels to the right ventricle which is then pumped through the pulmonary arteries to the lungs where gas exchange takes place and oxygen rich blood returns to the heart through the pulmonary veins into the left atrium and then the left ventricle which pumps oxygen rich blood to the rest of the body cells through the aorta.
The nervous system takes in information through our senses, processes the information and triggers reactions, such as making your muscles move or causing you to feel pain. For example, if you touch a hot plate, you reflexively pull back your hand and your nerves simultaneously send pain signals to your brain.
